Ti content in specimens of 80 grade wire cord steel was measured by laser ablation inductively coupled plasma mass spectrometry. It was found that the average Ti content increased and then decreased during electrical arc furnace (EAF) tappingRrefiningRcontinuous casting. Under current control condition of 80 grade wire cord steel in Nanjing Iron and Steel United Co. Ltd (NISUCL), the calculation results in several aspects such as formation thermodynamics, solidification segregation and growth kinetics of TiN particles showed that the formation of TiN only took place in the two-phase region where the solidification ratio is greater than 98%, or in solid phase region; both solidification segregation of Ti and N increased with increasing cooling rate and the segregation tendency was greater with increasing solidification fraction. The greater the cooling rate during solidification, the smaller the size of precipitated TiN particles. The size of precipitated TiN particles is 3-7 mm, which accorded with the size measured in metallographic image of TiN inclusions found in wire rod specimens.

TiAl alloys containing high Nb are significantly promising for high-temperature structural applications in aerospace and automotive industries. Unfortunately the low plasticity at room temperature limits their extensive applications. To improve the plasticity, not only optimizing the opposition, but also refining grain size through equal channel angular extrusion (ECAE) is necessary. The equal channel angular extrusion simulation of Ti-44Al-8Nb-(Cr,Mn,B,Y)(at%) alloy was investigated by using the Deform-3D software. The influences of friction coefficient, extrusion velocity, and different channel angles on effective strain, damage factor, and the load on the die were analyzed. The results indicate that, with the increasing of friction coefficient, effective strain is enhanced. The extrusion velocity has little effect on the uniformity of effective strain; in contrast it has large influence on the damage factor. Thus smaller extrusion rate is more appropriate. Under the condition of different channel angles, the larger one results in the lower effective strain magnitude and better strain distribution uniformity.

The as-cast microstructures, hot deformation behaviors and asdeformed microstructures of P-y TiAl alloys containing high niobium and various p stabilizing elements Mn, Cr, Mo and V were investigated. It is found that the increasing addition of Cr and Mo elements contributes to the continuous decrease of flow stress. On the contrary, with increasing the amount of V content, the flow stress enhances. In the Mn content addition range 0.5~2.0at%, the alloy with 1.5%Mn possesses the minimum value of flow stress. The optimum composition for hot working is Ti-44Al-8Nb-1.5Mn-0.2B-0.2Y. The morphology of P phase as well as the amount of P phase plays an important role in controlling the formability of P-y TiAl alloys containing high niobium.

The effect of different WC grain size additions on the microstructure and grain distribution of Ni–Co coarse crystalline cemented carbide was studied. And then the effect of grain distribution on the mechanical properties of cemented carbide was discussed. The effect of WC grain size on the grain size and coherency of cemented carbide was analyzed by microstructure. And the distribution of grains in the microstructure was investigated by the truncation method. The addition of fine (1.1–1.4 μm), medium (2.3–2.7 μm), and coarse WC (5.6–6.0 μm) particles can increase the nucleation rate of WC grains in the bonded phase. And the higher grain growth driving force can produce the theoretical limitation of nucleation and inhibit the coarsening of WC grains to a certain extent. The WC grain size has an insignificant effect on the frequency of the occurrence of super‐coarse grains in coarse crystalline cemented carbide. The average grain size and super coarse grains in microstructure gradually decrease, which promotes the improvement of transverse rupture strength. The increase of the adjacent degree and the decrease of the mean free path reduce which is beneficial to the improvement of the corrosion resistance of the alloy. The best overall performance of the alloy is achieved when fine‐grained WC is added.

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